Kageyama T, Takahashi K
J Biochem. 1980 Sep;88(3):635-45. doi: 10.1093/oxfordjournals.jbchem.a133014.
Pepsinogens were purified from the gastric mucosa of the crab-eating monkey, Macaca fascicularis. Eight pepsinogens were shown to be present disc-electrophoretically and they were termed pepsinogens I-a, I-b, III-1-a, III-1-b, III-2-a, III-2-b, III-3, and C, based on the nomenclature used for Japanese monkey pepsinogens. The molecular weights were 43,000 for pepsinogens I-a and I-b, 40,000 for pepsinogens III-1-a, III-1-b, III-2-a, III-2-b, and III-3, and 38,000 for pepsinogen C, as determined by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis. Pepsinogens I-a and I-b contained carbohydrate amounting to about 4-5% by weight. Each was activated to pepsin by acidification at pH 2.0. Pepsinogen III-1 (a mixture of III-1-a and III-1-b) yielded a single pepsin, i.e. pepsin III-1, and pepsinogen III-2 (a mixture of III-2-a and III-2-b) also gave a single pepsin, i.e. pepsin III-2. The molecular weights were estimated to be 38,000 for pepsins I-a and I-b, 35,000 for pepsins III-1, III-2, and III-3, and 34,000 for pepsin C. Optimal pHs toward acid-denatured hemoglobin were 1.9, 2.3, 2.0, 2.0, and 2.3 for pepsins I-a, III-1, III-2, III-3, and C, respectively. Pepstatin, diazoacetyl-DL-norleucine methyl ester (DAN), 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP), and p-bromophenacyl bromide inhibited each pepsin. Amino acid compositions of the pepsinogens and pepsins were determined. Pepsinogen C and pepsin C were distinct from the other pepsinogens and pepsins in their high ratios of glutamic acid to aspartic acid, and leucine to isoleucine. Amino acid sequences of the amino (N)-terminal 14 residues of pepsinogens were determined by the manual Edman procedure. One to three substitutions of amino acids were observed in the 14-residue segments among the pepsinogens except for pepsinogen C. There were 7 amino acid substitutions between pepsinogens C and III-3. These results suggest that the amino acid substitutions in the N-terminal region contribute considerably to the heterogeneity of pepsinogens.
从食蟹猴（猕猴）的胃黏膜中纯化出了胃蛋白酶原。通过圆盘电泳显示存在8种胃蛋白酶原，根据日本猴胃蛋白酶原的命名法，它们被命名为胃蛋白酶原I-a、I-b、III-1-a、III-1-b、III-2-a、III-2-b、III-3和C。通过十二烷基硫酸钠-聚丙烯酰胺圆盘凝胶电泳测定，胃蛋白酶原I-a和I-b的分子量为43,000，胃蛋白酶原III-1-a、III-1-b、III-2-a、III-2-b和III-3的分子量为40,000，胃蛋白酶原C的分子量为38,000。胃蛋白酶原I-a和I-b含有的碳水化合物约占重量的4 - 5%。每种在pH 2.0酸化时都被激活为胃蛋白酶。胃蛋白酶原III-1（III-1-a和III-1-b的混合物）产生单一的胃蛋白酶，即胃蛋白酶III-1，胃蛋白酶原III-2（III-2-a和III-2-b的混合物）也产生单一的胃蛋白酶，即胃蛋白酶III-2。胃蛋白酶I-a和I-b的分子量估计为38,000，胃蛋白酶III-1、III-2和III-3的分子量为35,000，胃蛋白酶C的分子量为34,000。胃蛋白酶I-a、III-1、III-2、III-3和C对酸变性血红蛋白的最适pH分别为1.9、2.3、2.0、2.0和2.3。胃抑素、重氮乙酰-DL-正亮氨酸甲酯（DAN）、1,2-环氧-3-(对硝基苯氧基)丙烷（EPNP）和对溴苯甲酰溴抑制每种胃蛋白酶。测定了胃蛋白酶原和胃蛋白酶的氨基酸组成。胃蛋白酶原C和胃蛋白酶C在谷氨酸与天冬氨酸以及亮氨酸与异亮氨酸的高比例方面与其他胃蛋白酶原和胃蛋白酶不同。通过手动埃德曼法测定了胃蛋白酶原氨基（N）末端14个残基的氨基酸序列。除胃蛋白酶原C外，在胃蛋白酶原的14个残基片段中观察到1至3个氨基酸取代。胃蛋白酶原C和III-3之间有7个氨基酸取代。这些结果表明N末端区域的氨基酸取代对胃蛋白酶原的异质性有很大贡献。
